The term 'Like the Lion's Share' refers to having the LARGEST portion of something. It is derived from the Aesop's fable, 'The Lion and the Mouse, ' in which a lion spares a mouse's life and the mouse later returns the favor by freeing the lion from a trap. In the story, the lion is rewarded with the lion's share of the reward for freeing him. This phrase has since been used to refer to someone or something having the LARGEST portion of something.